Valveless pump



E. THIELE VALVELESS PUMP March 6, 1962 2 Sheets-Sheet 1 Filed June 11,1958 l in INVENTOR ERNST THiE'LE' March 6, 1962 Filed June 11. 1958 E.THIELE VALVELESS PUMP 2 Sheets-Sheet 2 INVENTOR ERNST THIELE' ATTORNEYUnited States Patent 3,023,708 VALVELESS PUMP Ernst Thiele, 11Staudingergasse, Vienna, Austria Filed June 11, 1958, Ser. No. 741,262Claims priority, a plication Austria June 14, 1957 16 Claims. (Cl.103-53) This invention relates to pumps having liquid handling pistonsor diaphragms which oscillate at high speed and which are particularlydriven electromagnetically. in most types of pumps of this kind thedirection of handling is determined by valves, which are arranged eitherin the pipe system or in the oscillating piston itself. At least in thelatter case the piston has a through passage controlled by a valve. Allthese pumps have disadvantages which are peculiar to valve pumps andwhich reside in that the valve seats are liable to become leaky or thatthe valves can be clogged or highly stressed valve parts are liable tobreak. Besides, the valves oscillating at high speed must be ofparticularly light weight construction owing to the inertia and thesmall operating forces and for this reason will not withstandparticularly high stresses. Moreover, the efficiency of valves operatedat high speed is rather poor owing to the high velocities of flowtherethrough, involving high turbulence and a consumption of energy.

In order to avoid these disadvantages, valveless pumps have already beendescribed the oscillating pistons of which have also at least one flowpassage parallel to the piston axis. In these types of pumps thehandling is mainly due to the fact that the flow passage has the shapeof a nozzle tapering in the direction of flow. However, the handlingeffect of such pumps is very small and sufiicient only for a fewspecific purposes. Other solutions reside in that the piston hasimparted thereto a non-uniform motion, comprising a high speed forwardmovement and a slow return movement. These proposals have previouslyremained without significance, however, particularly because a directmechanical control of the piston or of a diaphragm involves mechanicaldifiiculties and an indirect electromagnetic control of this type iscomplicated.

It is an object of the invention to provide a valveless pump comprisinga cylinder, a member which oscillates in said cylinder at high speed andimparts motion to the liquid to be handled, at least one handling ductdisposed in the path of the moved liquid, and at least one stationaryconstriction in the discharge path close to the outlet opening of thehandling duct in the target direction of the liquid jet emerging fromsaid handling duct.

It is another object of the invention to drive the highspeed oscillatingpart electromagnetically according to a sine function.

According to the invention a considerable increase in the handlingeifect of such pumps is achieved in that at least one stationaryconstriction is arranged in the discharge path close to the outletopening of the handling duct in the target direction of the liquid jet,the crosssection of which constriction is approximately of the order ofmagnitude of the cross-section of the outlet openanother desirablefeature of the invention resides in that the constriction is formed bythe end of a duct which widens in the direction of how and is providedin a fitting. The fitting which is formed with the duct and theconstriction may be slidable in the cylinder or tube forming the liquidpath relative to the outlet opening of the flow passage in order toenable an adjustment. During operation the fitting is clamped inposition. According to another feature of the invention the inletpassage for the liquid is formed by that end of the cylinder which isopposite to the constriction.

3,023,708 Fatented Mar. 6, 1962 Some advantageous embodiments of theinvention are shown by way of example in the figures of the drawings insectional views taken through the center lines of the cylinders or pumptubes. FIG. 1 shows more particularly the arrangement of theconstriction in the form of a duct which widens in the direction of flowand FIG. 2 shows the pipeike extension of the fitting forming theconstriction, which extension extends into the outlet opening of thehandling duct. Both figures relate to pumps in which the inlet path forthe liquid is formed by that end of the cylinder which is opposite tothe constriction. FIGS. 3, 4 and 5 are diagrammatic views of differentcombinations of the several elements according to the invention. FIG. 3shows a pump having a cylinder which is closed at its rear end by abottom plate, and a piston provided with the outlet opening. FIG. 4shows a pump having a working diaphragm and an outlet opening fixedlyarranged in the pump tube. FIG. 5 shows another pump with a cylinder andan outlet opening arranged in the piston. In all pumps shown in FIGS. 3to 5 the liquid is supplied from the side through annular passages, andin the pump shown in FIG. 5 provision is also made for a supply ofliquid from the rear. Finally, FIG. 6 shows a particularly simple typeof construction of a pump, which extends partly into the vessel filledwith the liquid to be handled and which is directly fed with liquid fromthe side, whereas the other cylinder portion, which carries the drivesystem, not shown, extends out of the vessel. Arrows in the figures ofthe drawings indicate directions of flow of the liquid.

The valveless pump shown in FIG. 1 has a piston 11, which iselectromagnetically driven to oscillate at high speed and which isformed with a central handling duct 12, which extends in the directionof the axis of the piston and which tapers in the direction of flow. Thepiston 11 reciprocates slidingly in a cylinder 13 of low wall thicknessconsisting of non-magnetizable, preferably insulating material, throughwhich the magnetic fields of any known oscillation-producing drivesystem (not shown), which surrounds the cylinder, act on the piston 11,which consists, e.g., of insulating material and is surrounded by alongitudinally slotted shell 14 of sheet iron. Opposite to the outletopening 15 of the handling duct 12 a fixed constriction, particularly ofthe discharge path, is provided in the target direction of the liquidjet formed by the opening 15 near the forward dead center of the piston11, which is shown in this position. The cross-section of thisconstriction is approximately of the order of magnitude of thecross-section of the outlet opening 15. The constriction 16 is formed ina fitting 17 of rubber, plastic or the like, which is clamped inposition and is formed with a central duct 18, which follows theconstriction 1'6 and widens in the direction of flow. The fitting 17 mayserve for delimiting the oscillation of the piston 11 in one directionwhereas a stop 19, which consists, e.g., of a rubber ring, may bearranged on the other side. To enable an adjustment of the pump in thecylinder 13 the fitting 17 as well as the stop 19 are longitudinallydisplaceable relative to the magnetic system not shown. It issuflicient, however, if only the stop 19.is displaceable if the magneticdrive system itself is arranged to be displaceable for adjustment and tobe fixed in position for operation relative to the fitting 17, which inthis case may be fixedly arranged in the cylinder 13. The inlet path 33and the outlet path 43 open preferably into pipe connections not shown.

The mode of operation of such pump may be explained as follows: Duringthe movement of the piston in the direction toward the fitting 17 theliquid enclosed between the piston 11 and the fitting 17 is displacedand flows partly through the duct 18 and, in a smaller part through thehandling duct 12 owing to the inertia of the column of liquid flowing inthe discharge direction. When the piston is reversed the space enclosedbetween the piston 11 and the fitting 17 is enlarged. As a result of theinertia of theliquid column following up through the cylinder 13 and themovement of the piston opposite to this direction of flow, a sharp jetissues out of the small end 15 of the tapering handling duct 12. Thisjet is directed into the constriction 16 of the fitting 17 and preventsa backfiow of liquid from the same. Thus the inherentbackfiow-preventing action of the handling duct 12 is supported by theblocking action of the constriction 16 during the return movement of thepiston. For this reason the capacity and etficiency of such valvelesspumps are much higher than with the known valveless pumps.

The embodiment shown in FIG. 2 of the drawing proves particularlysatisfactory in those cases in which it is desired to utilize thetemporary formation of a jet at the small end 15 of the handling duct 12to retain rather than to compensate the highly pulsating liquidpressure. This applies, e.g., to room fountains with ejection nozzlesfrom which the liquid jet should emerge divided into as many finedroplets as possible. To this end a tubular extension 20 may be providedon the fitting 17 formed with the constriction 16. This extension may beprovided at that end of the fitting 17 which faces the oscillatingpiston 11 to extend into the outlet opening 15 of the handling duct 12in the front dead center position of the oscillating piston 11. The sameeffect will be obtained, e.g., if the tubular extension 20 is providedon the piston and extends into the constriction 16 at the end of thestroke.

Particularly favorable results will be obtained in all embodiments ofthe invention if the handling duct 12 as well as the duct 18 aredesigned according to flowdynamical considerations in order to avoidsuperfluous turbulence. This appears to be achieved best if said ductsare given the shape of nozzles. Pumps of this kind, in which the liquidis supplied from the rear, produce particularly favorable total heads.Where high capacities are more important, however, it has proveddesirable to supply the liquid to be handled from the side. Such pump isshown in FIG. 3. 'The piston 11 oscillating at high speed has at its endthe outlet opening 15, which is faced by the constriction 16. An annularinlet passage 22 is connected to the cylinder 13, which is tightlyclosed at its rear end by the bottom plate 26. This inlet passage 22enables a supply of liquid through the cylinder 13, which hasregistering holes or slots 24, or is interrupted at this point, into thespace between the outlet opening 15 and the constriction 16. The tubularextension 33 is connected to the inlet duct 22 and the tubular extension43 is connected to the cylinder 13 to form a discharge path.

FIG. 4 shows a pump which .is provided with a working diaphragm 21,which forms instead of the bottom plate 26 the closure of the tube 23.In this pump, which can bedriven by a drive system of particularlysimple construction, e.g., a solenoid, the fitting formed with theoutlet opening 15 is also fixedly arranged relative to the fittingformed with the constriction 16 and the annular inlet passage 22 isformed by these fittings and the tube 23, which has a lateral inletopening 24 and the pipe connection33. The discharge path is formed bythepipe connection 43. V

FIG. shows an embodiment of the pump according to the invention which issimilar to the pump according to FIG. 4. with respect tothe'construction of the annular inlet passage 24. This is a piston pumpthe piston 11 of which has at its conicalend facethe outlet opening 15so that the annular passage 22 is formed by the end .face of the piston11, the cylinder 13 and the fitting formed with the constriction 16. Thelateral supply is again effected through pipes 33 and holes or slots.24in the cylinder wall and the discharge path is formed by the pipeconnection 43. Liquid may also be supplied from the rear through abranch pipe or hose 33', which opens into an opening of the bottom plate26. This has the advantage that the discharge characteristics of thepump can be selectively varied by adjusting the valves 25, 25 arrangedin the two inlet pipes 33. When the valve 25 controlling the supply fromthe rear is closed and the lateral valve 25 is opened a large amount ofliquid will be handled whereas in the opposite valve position a largetotal head can be obtained with the same pump. It is obvious that valvepositions in which both inlet paths are more or less open are alsopossible and may bedesira-ble from time to time. It is particularlysuitable to couple the two valves for rotation or to provide a doublevalve so that both valves can be .adjusted in opposite senses by asingle manipulation.

It is also obvious that in the embodiments illustrated in FIGS. 3 to 5the outlet opening 15, the fittings formed with the outlet opening 15and with the constriction 16 as well as other components disposed in theliquid path are designed according to flow dynamical considerations, andmore particularly that the two fittings are adjustable. Finally, theinlet and outlet paths 33 and 43 may be designed differently from theform shown. They may consist, e.g., of shells fitted over the cylinder13 or the tube 23.

FIG. 6 shows a valveless pump in which the liquid to be handled isdirectly supplied from the side. In this case it is not necessary toprovide an annular inlet passage because that part of the cylinder 13which carries the inlet openings 24 extends into'the liquid-filled space28. This is tightly sealed by a wall 29 from the remaining part of thecylinder 13, which carries the piston and the drive means, not shown.The tight seal is elfected, e.g., by the nut 30 and the annular gasket31, which is forced against the collar 32 of the cylinder 13. The pumpcylinder is closed at the rear by the bottom plate 26. The elongatedpiston 11 carries the iron shell 14 for the drive and at its front endclose to the outlet opening 15 has slots 27 which register with theholes 24 in the walls of the cylinder 13 and enable the liquid to flowfrom the space 28 through the holes 24 into the handling duct 12. Inorder to eliminate the need for means for guiding the piston 11 along astraight line, the outside diameter of the piston is smaller adjacent tothe opening 27 or 24 than the inside diameter of the cylinder 13 so thatthere will be an open path for the liquid even if the openings 27 and 24have been relatively rotated. The other parts of the pump areconstructed in accordance with the embodiment shown in FIG. 2.

What is claimed is:

1. A valveless piston pump which comprises a cylinder having a wall ofnonmagnetizable material, a piston oscillating at high speed in saidcylinder in an axial direction and imparting movement to the liquid tobe conveyed, said piston containing magnetizable material for actuationby an external electromagnetic system, at least one liquid-handling ductextending through the piston and opening into a nozzlelike opening inthe end face of the piston, and a stationary transverse wall in thecylinder which has at. least one nozzlelike opening decreasing in sizetoward the piston in axialregistry with the opening in the end face ofthe piston and is connected to a duct for forwarding the liquid, theopening in the end face of the piston and the registering opening in thetransverse wall having approximately the same width and said openingslying close to each other when the piston is at its forward dead center.

2. A liquid pump according to claim 1 characterized in that the pistoncontains a single duct which tapers in streamline form in the. directionin which the liquid is conveyed and the center line of which coincideswith the center line of the piston.

3. A liquid pump according to claim 1 characterized in that thetransverse wall in the cylinder is formed by a plug which contains alsothe duct for forwarding the liquid and which is displaceable foradjustment in the cylinder whereas it is fixed in the cylinder duringthe operation of the pump.

4. A liquid pump according to claim 3 characterized in that the plug isclamped in the cylinder and forms the forward limitation for theoscillation of the piston during the operation of the pump.

5. A liquid pump according to claim 1 characterized in that theoscillation of the piston is limited at its end remote from the end faceby an annular stop which is fittingly inserted and clamped in thecylinder and forms the inlet.

6. A liquid pump according to claim 1 characterized in that lateralinlet openings for admitting the liquid are provided in a part of thewall of the cylinder.

7. A liquid pump according to claim 6 characterized in that said duct ofthe piston is provided with liquid entry openings in a side wall of thepiston and lateral to said nozzlelike opening, the lateral inlet openingof said cylinder being disposed to admit the liquid to the cylinder indirections toward said liquid entry openings in the piston.

8. A liquid pump according to claim 6 characterized in that the lateralinlet openings admit the liquid to the cylinder in a space between theend face of the piston and the transverse wall in the cylinder.

9. A liquid pump according to claim 7 characterized in that said liquidentry openings of the piston are larger than the inlet openings in thecylinder and remain in registry with the latter substantially throughoutthe travel of the piston during its oscillations.

10. A liquid pump according to claim 9 characterized in that the outsidediameter of the piston adjacent to the said liquid entry openings of thepiston is smaller than the inside diameter of the cylinder.

11. A liquid pump according to claim 6 characterized in that the saidpart of the wall of the cylinder which has the lateral inlet openingsextends into a space which is filled with the liquid to be conveyedwhereas the remaining part of the cylinder is disposed outside theliquid filled space for support of the external electromagnetic systemand is sealed by a partition from said space.

12. A liquid pump according to claim 6 characterized in that thecylinder is sealed by a bottom plate at the end in which the pistonoscillates.

13. A liquid pump according to claim 12 characterized in that the bottomplate which seals the cylinder is provided with an additional inletopening.

14. A liquid pump according to claim 1 characterized in that thecylinder is provided with a plurality of feed lines to permit entry of aliquid to the cylinder, said feed lines containing adjustable valves forregulating the rate of flow of entering liquid.

15. The pump of claim 1 comprising an extension pro jecting from one ofsaid ducts and extending into the other of said ducts when the piston isin its forwardmost position.

16. A fluid pump comprising a cylinder, a piston disposed in saidcylinder for axial reciprocating movement therein and provided with aninlet duct extending therethrough having a greater coefficient ofdischarge from inlet to outlet side than in the opposite direction, anoutlet duct aligned axially with said inlet duct having a greatercoefiicient of discharge from outlet to inlet side than in the oppositedirection, said ducts being close to each other when the piston is atits forwardmost position so that upon retracting movement of the pistona jet of fluid passes from said inlet duct to said outlet duct and uponforward movement of the piston a portion of the fluid between said ductsflows through said outlet duct.

References Cited in the file of this patent UNITED STATES PATENTS2,829,601 Weinfurt et a1 Apr. 8, 1958 2,872,877 Brewer Feb. 10, 1959FOREIGN PATENTS 705,667 Germany Mar. 27, 1941 780,157 Great Britain July31, 1957

